Reporting on quality of life in randomised controlled trials: bibliographic study

ObjectivesTo examine the frequency and quality of reporting on quality of life in randomised controlled trials.DesignSearch of the Cochrane Controlled Trials Register 1980 to 1997 to identify trials from all disciplines, from oncology, and from cardiovascular medicine that reported on quality of life. Assessment of abstracts from articles published from 1993 to 1996. Assessment of a sample of full reports with a standardised instrument.ResultsDuring 1980-97 reporting on quality of life increased from 0.63% to 4.2% for trials from all disciplines, from 1.5% to 8.2% for cancer trials, and from 0.34% to 3.6% for cardiovascular trials. Of 364 abstracts, 65% reported on drug interventions. Of a sample of 67 full reports, authors of 48 (72%) used 62 established quality of life instruments. In 15 reports (22%) authors developed their own measures, and in 2 (3%) methods were unclear. Response rates were given in 38 (57%), and complete reporting on all items and scales occurred in 31 (46%).ConclusionsLess than 5% of all randomised controlled trials reported on quality of life, and this proportion was below 10% even for cancer trials. A plethora of instruments was used in different studies, and the reporting of methods and results was often inadequate. Standards for the measurement and reporting of quality of life in clinical trials research need to be developed.

Key messages

• We examined the reporting on quality of life in randomised controlled trials listed in the Cochrane Controlled Trials Register
• Although reporting on quality of life increased over time, fewer than 5% of trials overall and fewer than 10% of cancer trials included quality of life in 1997
• Among 67 articles selected at random for detailed examination, a wide range of established and self developed measures of quality of life were used
• Only about half of trials gave response rates, and less than half reported on all items and scales used
• Standards for assessing and reporting quality of life in clinical research trials need to be developed

     

β Blockade after myocardial infarction: systematic review and meta regression analysis

ObjectivesTo assess the effectiveness of β blockers in short term treatment for acute myocardial infarction and in longer term secondary prevention; to examine predictive factors that may influence outcome and therefore choice of drug; and to examine the clinical importance of the results in the light of current treatment.DesignSystematic review of randomised controlled trials.SettingRandomised controlled trials.SubjectsPatients with acute or past myocardial infarction.Interventionβ Blockers compared with control.Mainoutcome measures All cause mortality and non-fatal reinfarction.ResultsOverall, 5477 of 54 234 patients (10.1%) randomised to β blockers or control died. We identified a 23% reduction in the odds of death in long term trials (95% confidence interval 15% to 31%), but only a 4% reduction in the odds of death in short term trials (−8% to 15%). Meta regression in long term trials did not identify a significant reduction in effectiveness in drugs with cardioselectivity but did identify a near significant trend towards decreased benefit in drugs with intrinsic sympathomimetic activity. Most evidence is available for propranolol, timolol, and metoprolol. In long term trials, the number needed to treat for 2 years to avoid a death is 42, which compares favourably with other treatments for patients with acute or past myocardial infarction.Conclusionsβ Blockers are effective in long term secondary prevention after myocardial infarction, but they are underused in such cases and lead to avoidable mortality and morbidity.

Key messages

• The first randomised trials of β blockade in secondary prevention after myocardial infarction were published in the 1960s
• β blockers were once heralded as a major advance, but their use for secondary prevention has declined in recent years
• Firm evidence shows that long term β blockade remains an effective and well tolerated treatment that reduces mortality and morbidity in unselected patients after myocardial infarction
• The benefits from β blockade compare favourably with other drug treatments for this patient group
• Most evidence is for propranolol, timolol, and metoprolol, whereas atenolol, which is commonly used, is inadequately evaluated for long term use

     

What is meant by intention to treat analysis? Survey of published randomised controlled trials

ObjectivesTo assess the methodological quality of intention to treat analysis as reported in randomised controlled trials in four large medical journals.DesignSurvey of all reports of randomised controlled trials published in 1997 in the BMJ, Lancet, JAMA, and New England Journal of Medicine.Results119 (48%) of the reports mentioned intention to treat analysis. Of these, 12 excluded any patients who did not start the allocated intervention and three did not analyse all randomised subjects as allocated. Five reports explicitly stated that there were no deviations from random allocation. The remaining 99 reports seemed to analyse according to random allocation, but only 34 of these explicitly stated this. 89 (75%) trials had some missing data on the primary outcome variable. The methods used to deal with this were generally inadequate, potentially leading to a biased treatment effect. 29 (24%) trials had more than 10% of responses missing for the primary outcome, the methods of handling the missing responses were similar in this subset.ConclusionsThe intention to treat approach is often inadequately described and inadequately applied. Authors should explicitly describe the handling of deviations from randomised allocation and missing responses and discuss the potential effect of any missing response. Readers should critically assess the validity of reported intention to treat analyses.

Key messages

• Intention to treat gives a pragmatic estimate of the benefit of a change in treatment policy rather than of potential benefit in patients who receive treatment exactly as planned
• Full application of intention to treat is possible only when complete outcome data are available for all randomised subjects
• About half of all published reports of randomised controlled trials stated that intention to treat was used, but handling of deviations from randomised allocation varied widely
• Many trials had some missing data on the primary outcome variable, and methods used to deal with this were generally inadequate, potentially leading to bias
• Intention to treat analyses are often inadequately described and inadequately applied

     

The unpredictability paradox: review of empirical comparisons of randomised and non-randomised clinical trials

Objective To summarise comparisons of randomised clinical trials and non-randomised clinical trials, trials with adequately concealed random allocation versus inadequately concealed random allocation, and high quality trials versus low quality trials where the effect of randomisation could not be separated from the effects of other methodological manoeuvres.Design Systematic review.Selection criteria Cohorts or meta-analyses of clinical trials that included an empirical assessment of the relation between randomisation and estimates of effect.Data sources Cochrane Review Methodology Database, Medline, SciSearch, bibliographies, hand searching of journals, personal communication with methodologists, and the reference lists of relevant articles.Main outcome measures Relation between randomisation and estimates of effect.Results Eleven studies that compared randomised controlled trials with non-randomised controlled trials (eight for evaluations of the same intervention and three across different interventions), two studies that compared trials with adequately concealed random allocation and inadequately concealed random allocation, and five studies that assessed the relation between quality scores and estimates of treatment effects, were identified. Failure to use random allocation and concealment of allocation were associated with relative increases in estimates of effects of 150% or more, relative decreases of up to 90%, inversion of the estimated effect and, in some cases, no difference. On average, failure to use randomisation or adequate concealment of allocation resulted in larger estimates of effect due to a poorer prognosis in non-randomly selected control groups compared with randomly selected control groups.Conclusions Failure to use adequately concealed random allocation can distort the apparent effects of care in either direction, causing the effects to seem either larger or smaller than they really are. The size of these distortions can be as large as or larger than the size of the effects that are to be detected.

Key messages

• Empirical studies support using random allocation in clinical trials and ensuring that the allocation process is concealed—that is, that assignment is impervious to any influence by the people making the allocation
• The effect of not using concealed random allocation can be as large or larger than the effects of worthwhile interventions
• On average, failure to use concealed random allocation results in overestimates of effect due to a poorer prognosis in non-randomly selected control groups compared with randomly selected control groups, but it can result in underestimates of effect, reverse the direction of effect, mask an effect, or give similar estimates of effect
• The adequacy of allocation concealment may be a more sensitive measure of bias in clinical trials than scales used to assess the quality of clinical trials
• It is a paradox that the unpredictability of randomisation is the best protection against the unpredictability of the extent and direction of bias in clinical trials that are not properly randomised

     

Human albumin administration in critically ill patients: systematic review of randomised controlled trials

Objective: To quantify effect on mortality of administering human albumin or plasma protein fraction during management of critically ill patients. Design: Systematic review of randomised controlled trials comparing administration of albumin or plasma protein fraction with no administration or with administration of crystalloid solution in critically ill patients with hypovolaemia, burns, or hypoalbuminaemia. Subjects: 30 randomised controlled trials including 1419 randomised patients. Main outcome measure: Mortality from all causes at end of follow up for each trial. Results: For each patient category the risk of death in the albumin treated group was higher than in the comparison group. For hypovolaemia the relative risk of death after albumin administration was 1.46 (95% confidence interval 0.97 to 2.22), for burns the relative risk was 2.40 (1.11 to 5.19), and for hypoalbuminaemia it was 1.69 (1.07 to 2.67). Pooled relative risk of death with albumin administration was 1.68 (1.26 to 2.23). Pooled difference in the risk of death with albumin was 6% (95% confidence interval 3% to 9%) with a fixed effects model. These data suggest that for every 17 critically ill patients treated with albumin there is one additional death. Conclusions: There is no evidence that albumin administration reduces mortality in critically ill patients with hypovolaemia, burns, or hypoalbuminaemia and a strong suggestion that it may increase mortality. These data suggest that use of human albumin in critically ill patients should be urgently reviewed and that it should not be used outside the context of rigorously conducted, randomised controlled trials.

Key messages

• Human albumin solution has been used in the treatment of critically ill patients for over 50 years
• Currently, the licensed indications for use of albumin are emergency treatment of shock, acute management of burns, and clinical situations associated with hypoproteinaemia
• Our systematic review of randomised controlled trials showed that, for each of these patient categories, the risk of death in the albumin treated group was higher than in the comparison group
• The pooled relative risk of death with albumin was 1.68 (95% confidence interval 1.26 to 2.23) and the pooled difference in the risk of death was 6% (3% to 9%) or six additional deaths for every 100 patients treated
• We consider that use of human albumin solution in critically ill patients should be urgently reviewed

     

Systematic review of dietary intervention trials to lower blood total cholesterol in free-living subjects

Objectives: To estimate the efficacy of dietary advice to lower blood total cholesterol concentration in free-living subjects and to investigate the efficacy of different dietary recommendations. Design: Systematic overview of 19 randomised controlled trials including 28 comparisons. Subjects: Free-living subjects. Interventions: Individualised dietary advice to modify fat intake. Main outcome measure: Percentage difference in blood total cholesterol concentration between the intervention and control groups. Results: The percentage reduction in blood total cholesterol attributable to dietary advice after at least six months of intervention was 5.3% (95% confidence interval 4.7% to 5.9%). Including both short and long duration studies, the effect was 8.5% at 3 months and 5.5% at 12 months. Diets equivalent to the step 2 diet of the American Heart Association were of similar efficacy to diets that aimed to lower total fat intake or to raise the polyunsaturated to saturated fatty acid ratio. These diets were moderately more effective than the step 1 diet of the American Heart Association (6.1% v 3.0% reduction in blood total cholesterol concentration; P<0.0001). On the basis of reported food intake, the targets for dietary change were seldom achieved. The observed reductions in blood total cholesterol concentrations in the individual trials were consistent with those predicted from dietary intake on the basis of the Keys equation. Conclusions: Individualised dietary advice for reducing cholesterol concentration is modestly effective in free-living subjects. More intensive diets achieve a greater reduction in serum cholesterol concentration. Failure to comply fully with dietary recommendations is the likely explanation for this limited efficacy.

Key messages

• Results from metabolic ward studies suggest that dietary change can reduce blood cholesterol concentrations by up to 15%
• In free-living subjects the standard step 1 diet of the American Heart Association lowers cholesterol concentration by about 3%, and about another 3% can be achieved with more intensive diets
• Difficulties in complying with the prescribed dietary change explain the failure to achieve the expected reductions in cholesterol concentrations
• It is important to be realistic about the reductions in cardiovascular risk that can be achieved by individual dietary counselling

     

Lowering blood homocysteine with folic acid based supplements: meta-analysis of randomised trials

Objective: To determine the size of reduction in homocysteine concentrations produced by dietary supplementation with folic acid and with vitamins B-12 or B-6. Design: Meta-analysis of randomised controlled trials that assessed the effects of folic acid based supplements on blood homocysteine concentrations. Multivariate regression analysis was used to determine the effects on homocysteine concentrations of different doses of folic acid and of the addition of vitamin B-12 or B-6. Subjects: Individual data on 1114 people included in 12 trials. Findings: The proportional and absolute reductions in blood homocysteine produced by folic acid supplements were greater at higher pretreatment blood homocysteine concentrations (P<0.001) and at lower pretreatment blood folate concentrations (P<0.001). After standardisation to pretreatment blood concentrations of homocysteine of 12 μmol/l and of folate of 12 nmol/l (approximate average concentrations for Western populations), dietary folic acid reduced blood homocysteine concentrations by 25% (95% confidence interval 23% to 28%; P<0.001), with similar effects in the range of 0.5-5 mg folic acid daily. Vitamin B-12 (mean 0.5 mg daily) produced an additional 7% (3% to 10%) reduction in blood homocysteine. Vitamin B-6 (mean 16.5 mg daily) did not have a significant additional effect. Conclusions: Typically in Western populations, daily supplementation with both 0.5-5 mg folic acid and about 0.5 mg vitamin B-12 would be expected to reduce blood homocysteine concentrations by about a quarter to a third (for example, from about 12 μmol/l to 8-9 μmol/l). Large scale randomised trials of such regimens in high risk populations are now needed to determine whether lowering blood homocysteine concentrations reduces the risk of vascular disease.

Key messages

• Higher blood homocysteine concentrations seem to be associated with higher risks of occlusive vascular disease and with lower blood concentrations of folate and vitamins B-12 and B-6
• Proportional and absolute reductions in blood homocysteine concentrations with folic acid supplements are greater at higher pretreatment blood homocysteine concentrations and at lower pretreatment blood folate concentrations
• In typical Western populations, supplementation with both 0.5-5 mg daily folic acid and about 0.5 mg daily vitamin B-12 should reduce blood homocysteine concentrations by about a quarter to a third
• Large scale randomised trials of such regimens in people at high risk are now needed to determine whether lowering blood homocysteine concentrations reduces the risk of vascular disease

     

Trial Publication after Registration in ClinicalTrials.Gov: A Cross-Sectional Analysis

Background

ClinicalTrials.gov is a publicly accessible, Internet-based registry of clinical trials managed by the US National Library of Medicine that has the potential to address selective trial publication. Our objectives were to examine completeness of registration within ClinicalTrials.gov and to determine the extent and correlates of selective publication.

Methods and Findings

We examined reporting of registration information among a cross-section of trials that had been registered at ClinicalTrials.gov after December 31, 1999 and updated as having been completed by June 8, 2007, excluding phase I trials. We then determined publication status among a random 10% subsample by searching MEDLINE using a systematic protocol, after excluding trials completed after December 31, 2005 to allow at least 2 y for publication following completion. Among the full sample of completed trials (n = 7,515), nearly 100% reported all data elements mandated by ClinicalTrials.gov, such as intervention and sponsorship. Optional data element reporting varied, with 53% reporting trial end date, 66% reporting primary outcome, and 87% reporting trial start date. Among the 10% subsample, less than half (311 of 677, 46%) of trials were published, among which 96 (31%) provided a citation within ClinicalTrials.gov of a publication describing trial results. Trials primarily sponsored by industry (40%, 144 of 357) were less likely to be published when compared with nonindustry/nongovernment sponsored trials (56%, 110 of 198; p<0.001), but there was no significant difference when compared with government sponsored trials (47%, 57 of 122; p = 0.22). Among trials that reported an end date, 75 of 123 (61%) completed prior to 2004, 50 of 96 (52%) completed during 2004, and 62 of 149 (42%) completed during 2005 were published (p = 0.006).

Conclusions

Reporting of optional data elements varied and publication rates among completed trials registered within ClinicalTrials.gov were low. Without greater attention to reporting of all data elements, the potential for ClinicalTrials.gov to address selective publication of clinical trials will be limited. Please see later in the article for the Editors'' Summary     

Prospective,randomised, double blind trial of prophylaxis with single dose of co-amoxiclav before percutaneous endoscopic gastrostomy

ObjectiveTo determine the efficacy of antibacterial prophylaxis in preventing infectious complications after percutaneous endoscopic gastrostomy.DesignProspective, randomised, placebo controlled, double blind, multicentre study.SettingDepartments of internal medicine at six German hospitals.SubjectsOf 106 randomised adult patients with dysphagia, 97 received study medication, and 84 completed the study. The median age of the patients was 65 years. Most had dysphagia due to malignant disease (65%), and many (76%) had serious comorbidity.InterventionsA single intravenous 2.2 g dose of co-amoxiclav or identical appearing saline was given 30 min before percutaneous endoscopic gastrostomy performed by the thread pull method.ResultsThe incidence of peristomal and other infections within one week after percutaneous endoscopic gastrostomy was significantly reduced in the antibiotic group (8/41 (20%) v 28/43 (65%), P<0.001). Similar results were obtained in an intention to treat analysis. Several peristomal wound infections were of minor clinical significance. After wound infections that required no or only local treatment were excluded from the analysis, antibiotic prophylaxis remained highly effective in reducing clinically important wound infections (1/41 (2%) v 11/43 (26%), P<0.01) and non-wound infections (2 (5%) v 9 (21%), P<0.05).ConclusionsAntibiotic prophylaxis with a single dose of co-amoxiclav significantly reduces the risk of infectious complications after percutaneous endoscopic gastrostomy and should be recommended.

Key messages

• Percutaneous endoscopic gastrostomy for enteral feeding can be associated with substantial rates of infectious complications, notably peristomal wound infection
• Small, single centre studies on prevention of wound infection by antibiotic prophylaxis have given conflicting results
• This prospective, randomised, placebo controlled, double blind, multicentre study showed that a single dose of 2.2 g co-amoxiclav significantly reduced the rate of infection
• The favourable effect of antibiotic prophylaxis included a reduction in the rate of clinically important peristomal wound infection
• Intention to treat analysis indicated a significant reduction in the need for therapeutic antibiotics

     

Effectiveness of treatments for infantile colic: systematic review

Objective: To evaluate the effectiveness of diets, drug treatment, and behavioural interventions on infantile colic in trials with crying or the presence of colic as the primary outcome measure. Data sources: Controlled clinical trials identified by a highly sensitive search strategy in Medline (1966-96), Embase (1986-95), and the Cochrane Controlled Trials Register, in combination with reference checking for further relevant publications. Keywords were crying and colic. Study selection: Two independent assessors selected controlled trials with interventions lasting at least 3 days that included infants younger than 6 months who cried excessively. Data synthesis: Methodological quality was assessed by two assessors independently with a quality assessment scale (range 0-5). Effect sizes were calculated as percentage success. Effect sizes of trials using identical interventions were pooled using a random effects model. Results: 27 controlled trials were identified. Elimination of cows’ milk protein was effective when substituted by hypoallergenic formula milks (effect size 0.22 (95% confidence interval 0.09 to 0.34)). The effectiveness of substitution by soy formula milks was unclear when only trials of good methodological quality were considered. The benefit of eliminating cows’ milk protein was not restricted to highly selected populations. Dicyclomine was effective (effect size 0.46 ( 0.33 to 0.60)), but serious side effects have been reported. The advice to reduce stimulation was beneficial (effect size 0.48 (0.23 to 0.74)), whereas the advice to increase carrying and holding seemed not to reduce crying. No benefit was shown for simethicone. Uncertainty remained about the effectiveness of low lactose formula milks. Conclusions: Infantile colic should preferably be treated by advising carers to reduce stimulation and with a one week trial of a hypoallergenic formula milk.

Key messages

• Infantile colic is common during the first months of life, but its cause is unknown
• A definite diagnosis of infantile colic should be followed by a one week trial of substituting cows’ milk with hypoallergenic formula milk
• Dietary intervention should be combined with behavioural interventions: general advice, reassurance, reduction in stimuli, and sensitive differential responding (teaching parents to be more appropriately responsive to their infants with less overstimulation and more effective soothing)
• Anticholinergic drugs are not recommended because of their serious side effects

     

Testing for Helicobacter pylori infection: validation and diagnostic yield of a near patient test in primary care

ObjectiveTo evaluate the performance of a near patient test for Helicobacter pylori infection in primary care.DesignValidation study performed within a randomised trial of four management strategies for dyspepsia.Setting43 general practices around Nottingham.Subjects394 patients aged 18-70 years presenting with recent onset dyspepsia.ResultsWhen used in primary care FlexSure test had a sensitivity and specificity of 67% (95% confidence interval 59% to 75%) and 98% (95% to 99%) compared with a sensitivity and specificity of 92% (87% to 97%) and 90% (83% to 97%) when used previously in secondary care. Of the H pylori test and refer group 14% (28/199) were found to have conditions for which H pylori eradication was appropriate compared with 23% (39/170) of the group referred directly for endoscopy.ConclusionsWhen used in primary care the sensitivity of the FlexSure test was significantly poorer than in secondary care. About a third of patients who would have benefited from H pylori eradication were not detected. Near patient tests need to be validated in primary care before they are incorporated into management policies for dyspepsia.

Key messages

• Near patient tests for H pylori infection have been recommended in the management of dyspepsia in primary care without proper evaluation
• Such tests should have a high sensitivity to avoid missing treatable illness related to infection
• The FlexSure near patient test had a lower sensitivity than previously reported in validation studies performed in secondary care
• Fewer than expected numbers of patients with H pylori related pathology were identified with the FlexSure in primary care

     

Vertical transmission rates for HIV in the British Isles: estimates based on surveillance data

ObjectiveTo estimate and interpret time trends in vertical transmission rates for HIV using data from national obstetric and paediatric surveillance registers.DesignProspective study of HIV infected women reported through obstetric surveillance. HIV infection status of the child and onset of AIDS were reported through paediatric surveillance. Rates of vertical transmission and progression to AIDS rate were estimated by methods that take account of incomplete follow up of children with indeterminate infection status and delay in AIDS reporting.SettingBritish Isles.SubjectsPregnant women infected with HIV whose infection was diagnosed before delivery, and their babies.ResultsBy January 1999, 800 children born to diagnosed HIV infected women who had not breast fed had been reported. Vertical transmission rates rose to 19.6% (95% confidence interval 8.0% to 32.5%) in 1993 before falling to 2.2% (0% to 7.8%) in 1998. Between 1995 and 1998 use of antiretroviral treatment increased significantly each year, reaching 97% of live births in 1998. The rate of elective caesarean section remained constant, at around 40%, up to 1997 but increased to 62% in 1998. Caesarean section and antiretroviral treatment together were estimated to reduce risk of transmission from 31.6% (13.6% to 52.2%) to 4.2% (0.8% to 8.5%). The proportion of infected children developing AIDS in the first 6 months fell from 17.7% (6.8% to 30.8%) before 1994 to 7.2% (0% to 15.7%) after, coinciding with increased use of prophylaxis against Pneumocystis carinii pneumonia.ConclusionsIn the British Isles both HIV related morbidity and vertical transmission are being reduced through increased use of interventions.

Key messages

• Reliable estimates of HIV vertical transmission rates can be derived from surveillance data
• Infected pregnant women are increasingly taking up elective caesarean section and antiretroviral treatment to reduce the risk of transmitting HIV to their babies
• Vertical transmission rates have fallen greatly over the past four years and progression to AIDS among infected children may also have slowed
• These benefits can occur only if infected women are diagnosed before or during pregnancy

     

Efficacy,tolerability, and upper gastrointestinal safety of celecoxib for treatment of osteoarthritis and rheumatoid arthritis: systematic review of randomised controlled trials

ObjectiveTo determine the efficacy, gastrointestinal safety, and tolerability of celecoxib (a cyclo-oxygenase 2 (COX 2) inhibitor) used in the treatment of osteoarthritis and rheumatoid arthritis.DesignSystematic review of randomised trials that compared at least 12 weeks'' celecoxib treatment with another non-steroidal anti-inflammatory drug (NSAID) or placebo and reported efficacy, tolerability, or safety. Trials identified from manufacturer and by searching electronic databases and evaluated according to predefined inclusion and quality criteria. Data combined through meta-analysis.Participants15 187 patients with osteoarthritis or rheumatoid arthritis.ResultsNine randomised controlled trials were included. Celecoxib and NSAIDS were equally effective for all efficacy outcomes. Compared with those taking other NSAIDs, in patients taking celecoxib the rate of withdrawals due to adverse gastrointestinal events was 46% lower (95% confidence interval 29% to 58%; NNT 35 at three months), the incidence of ulcers detectable by endoscopy was 71% lower (59% to 79%; NNT 6 at three months), and the incidence of symptoms of ulcers, perforations, bleeds, and obstructions was 39% lower (4% to 61%; NNT 208 at six months). Subgroup analysis of patients taking aspirin showed that the incidence of ulcers detected by endoscopy was reduced by 51% (14% to 72%) in those given celecoxib compared with other NSAIDs. The reduction was greater (73%, 52% to 84%) in those not taking aspirin.ConclusionCelecoxib is as effective as other NSAIDs for relief of symptoms of osteoarthritis and rheumatoid arthritis and has significantly improved gastrointestinal safety and tolerability.

What is already known on this topic

Long term NSAID use is associated with the development of peptic and duodenal ulcersCOX 2 specific inhibitors are claimed to cause fewer gastrointestinal complicationsThe National Institute for Clinical Excellence has recently recommended that COX 2 specific inhibitors are used in patients with arthritis who are at risk of gastrointestinal complications but not in those taking prophylactic aspirin

What this study adds

Systematic review of randomised trials shows that celecoxib is as effective as other NSAIDs for osteoarthritis and rheumatoid arthritisCelecoxib has significantly improved gastrointestinal safety and tolerability compared with standard NSAIDsAn improvement in gastrointestinal safety was still evident in patients who were also taking aspirin     

Reporting Bias in Drug Trials Submitted to the Food and Drug Administration: Review of Publication and Presentation

Background

Previous studies of drug trials submitted to regulatory authorities have documented selective reporting of both entire trials and favorable results. The objective of this study is to determine the publication rate of efficacy trials submitted to the Food and Drug Administration (FDA) in approved New Drug Applications (NDAs) and to compare the trial characteristics as reported by the FDA with those reported in publications.

Methods and Findings

This is an observational study of all efficacy trials found in approved NDAs for New Molecular Entities (NMEs) from 2001 to 2002 inclusive and all published clinical trials corresponding to the trials within the NDAs. For each trial included in the NDA, we assessed its publication status, primary outcome(s) reported and their statistical significance, and conclusions. Seventy-eight percent (128/164) of efficacy trials contained in FDA reviews of NDAs were published. In a multivariate model, trials with favorable primary outcomes (OR = 4.7, 95% confidence interval [CI] 1.33–17.1, p = 0.018) and active controls (OR = 3.4, 95% CI 1.02–11.2, p = 0.047) were more likely to be published. Forty-one primary outcomes from the NDAs were omitted from the papers. Papers included 155 outcomes that were in the NDAs, 15 additional outcomes that favored the test drug, and two other neutral or unknown additional outcomes. Excluding outcomes with unknown significance, there were 43 outcomes in the NDAs that did not favor the NDA drug. Of these, 20 (47%) were not included in the papers. The statistical significance of five of the remaining 23 outcomes (22%) changed between the NDA and the paper, with four changing to favor the test drug in the paper (p = 0.38). Excluding unknowns, 99 conclusions were provided in both NDAs and papers, nine conclusions (9%) changed from the FDA review of the NDA to the paper, and all nine did so to favor the test drug (100%, 95% CI 72%–100%, p = 0.0039).

Conclusions

Many trials were still not published 5 y after FDA approval. Discrepancies between the trial information reviewed by the FDA and information found in published trials tended to lead to more favorable presentations of the NDA drugs in the publications. Thus, the information that is readily available in the scientific literature to health care professionals is incomplete and potentially biased.